1BATMAN-ADV
2----------
3 4Batman advanced is a new approach to wireless networking which
5does no longer operate on the IP basis. Unlike the batman daemon,
6which exchanges information using UDP packets and sets routing
7tables, batman-advanced operates on ISO/OSI Layer 2 only and uses
8and routes (or better: bridges) Ethernet Frames. It emulates a
9virtual network switch of all nodes participating. Therefore all
10nodes appear to be link local, thus all higher operating proto-
11cols won't be affected by any changes within the network. You can
12run almost any protocol above batman advanced, prominent examples
13are: IPv4, IPv6, DHCP, IPX.
14 15Batman advanced was implemented as a Linux kernel driver to re-
16duce the overhead to a minimum. It does not depend on any (other)
17network driver, and can be used on wifi as well as ethernet lan,
18vpn, etc ... (anything with ethernet-style layer 2).
19 20 21CONFIGURATION
22-------------
23 24Load the batman-adv module into your kernel:
25 26# insmod batman-adv.ko
27 28The module is now waiting for activation. You must add some in-
29terfaces on which batman can operate. After loading the module
30batman advanced will scan your systems interfaces to search for
31compatible interfaces. Once found, it will create subfolders in
32the /sys directories of each supported interface, e.g.
33 34# ls /sys/class/net/eth0/batman_adv/
35# iface_status mesh_iface
36 37If an interface does not have the "batman_adv" subfolder it prob-
38ably is not supported. Not supported interfaces are: loopback,
39non-ethernet and batman's own interfaces.
40 41Note: After the module was loaded it will continuously watch for
42new interfaces to verify the compatibility. There is no need to
43reload the module if you plug your USB wifi adapter into your ma-
44chine after batman advanced was initially loaded.
45 46To activate a given interface simply write "bat0" into its
47"mesh_iface" file inside the batman_adv subfolder:
48 49# echo bat0 > /sys/class/net/eth0/batman_adv/mesh_iface
50 51Repeat this step for all interfaces you wish to add. Now batman
52starts using/broadcasting on this/these interface(s).
53 54By reading the "iface_status" file you can check its status:
55 56# cat /sys/class/net/eth0/batman_adv/iface_status
57# active
58 59To deactivate an interface you have to write "none" into its
60"mesh_iface" file:
61 62# echo none > /sys/class/net/eth0/batman_adv/mesh_iface
63 64 65All mesh wide settings can be found in batman's own interface
66folder:
67 68# ls /sys/class/net/bat0/mesh/
69# aggregated_ogms gw_bandwidth log_level
70# ap_isolation gw_mode orig_interval
71# bonding gw_sel_class routing_algo
72# bridge_loop_avoidance hop_penalty vis_mode
73# fragmentation
74 75 76There is a special folder for debugging information:
77 78# ls /sys/kernel/debug/batman_adv/bat0/
79# bla_claim_table log socket transtable_local
80# gateways originators transtable_global vis_data
81 82Some of the files contain all sort of status information regard-
83ing the mesh network. For example, you can view the table of
84originators (mesh participants) with:
85 86# cat /sys/kernel/debug/batman_adv/bat0/originators
87 88Other files allow to change batman's behaviour to better fit your
89requirements. For instance, you can check the current originator
90interval (value in milliseconds which determines how often batman
91sends its broadcast packets):
92 93# cat /sys/class/net/bat0/mesh/orig_interval
94# 1000
95 96and also change its value:
97 98# echo 3000 > /sys/class/net/bat0/mesh/orig_interval
99 100In very mobile scenarios, you might want to adjust the originator
101interval to a lower value. This will make the mesh more respon-
102sive to topology changes, but will also increase the overhead.
103 104 105USAGE
106-----
107 108To make use of your newly created mesh, batman advanced provides
109a new interface "bat0" which you should use from this point on.
110All interfaces added to batman advanced are not relevant any
111longer because batman handles them for you. Basically, one "hands
112over" the data by using the batman interface and batman will make
113sure it reaches its destination.
114 115The "bat0" interface can be used like any other regular inter-
116face. It needs an IP address which can be either statically con-
117figured or dynamically (by using DHCP or similar services):
118 119# NodeA: ifconfig bat0 192.168.0.1
120# NodeB: ifconfig bat0 192.168.0.2
121# NodeB: ping 192.168.0.1
122 123Note: In order to avoid problems remove all IP addresses previ-
124ously assigned to interfaces now used by batman advanced, e.g.
125 126# ifconfig eth0 0.0.0.0
127 128 129VISUALIZATION
130-------------
131 132If you want topology visualization, at least one mesh node must
133be configured as VIS-server:
134 135# echo "server" > /sys/class/net/bat0/mesh/vis_mode
136 137Each node is either configured as "server" or as "client" (de-
138fault: "client"). Clients send their topology data to the server
139next to them, and server synchronize with other servers. If there
140is no server configured (default) within the mesh, no topology
141information will be transmitted. With these "synchronizing
142servers", there can be 1 or more vis servers sharing the same (or
143at least very similar) data.
144 145When configured as server, you can get a topology snapshot of
146your mesh:
147 148# cat /sys/kernel/debug/batman_adv/bat0/vis_data
149 150This raw output is intended to be easily parsable and convertable
151with other tools. Have a look at the batctl README if you want a
152vis output in dot or json format for instance and how those out-
153puts could then be visualised in an image.
154 155The raw format consists of comma separated values per entry where
156each entry is giving information about a certain source inter-
157face. Each entry can/has to have the following values:
158-> "mac" - mac address of an originator's source interface
159 (each line begins with it)
160-> "TQ mac value" - src mac's link quality towards mac address
161 of a neighbor originator's interface which
162 is being used for routing
163-> "TT mac" - TT announced by source mac
164-> "PRIMARY" - this is a primary interface
165-> "SEC mac" - secondary mac address of source
166 (requires preceding PRIMARY)
167 168The TQ value has a range from 4 to 255 with 255 being the best.
169The TT entries are showing which hosts are connected to the mesh
170via bat0 or being bridged into the mesh network. The PRIMARY/SEC
171values are only applied on primary interfaces
172 173 174LOGGING/DEBUGGING
175-----------------
176 177All error messages, warnings and information messages are sent to
178the kernel log. Depending on your operating system distribution
179this can be read in one of a number of ways. Try using the com-
180mands: dmesg, logread, or looking in the files /var/log/kern.log
181or /var/log/syslog. All batman-adv messages are prefixed with
182"batman-adv:" So to see just these messages try
183 184# dmesg | grep batman-adv
185 186When investigating problems with your mesh network it is some-
187times necessary to see more detail debug messages. This must be
188enabled when compiling the batman-adv module. When building bat-
189man-adv as part of kernel, use "make menuconfig" and enable the
190option "B.A.T.M.A.N. debugging".
191 192Those additional debug messages can be accessed using a special
193file in debugfs
194 195# cat /sys/kernel/debug/batman_adv/bat0/log
196 197The additional debug output is by default disabled. It can be en-
198abled during run time. Following log_levels are defined:
199 2000 - All debug output disabled
2011 - Enable messages related to routing / flooding / broadcasting
2022 - Enable messages related to route added / changed / deleted
2034 - Enable messages related to translation table operations
2048 - Enable messages related to bridge loop avoidance
20515 - enable all messages
206 207The debug output can be changed at runtime using the file
208/sys/class/net/bat0/mesh/log_level. e.g.
209 210# echo 6 > /sys/class/net/bat0/mesh/log_level
211 212will enable debug messages for when routes change.
213 214Counters for different types of packets entering and leaving the
215batman-adv module are available through ethtool:
216 217# ethtool --statistics bat0
218 219 220BATCTL
221------
222 223As batman advanced operates on layer 2 all hosts participating in
224the virtual switch are completely transparent for all protocols
225above layer 2. Therefore the common diagnosis tools do not work
226as expected. To overcome these problems batctl was created. At
227the moment the batctl contains ping, traceroute, tcpdump and
228interfaces to the kernel module settings.
229 230For more information, please see the manpage (man batctl).
231 232batctl is available on http://www.open-mesh.org/ 233 234 235CONTACT
236-------
237 238Please send us comments, experiences, questions, anything :)
239 240IRC: #batman on irc.freenode.org
241Mailing-list: b.a.t.m.a.n@open-mesh.org (optional subscription
242 at https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
243 244You can also contact the Authors:
245 246Marek Lindner <lindner_marek@yahoo.de>
247Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
248